Heptyl phenol alkylation

ABSTRACT

A C7 HEART CUT OF CATALYTIC GASOLINE CONTAINING LARGE QUANITIES OF OLEFINES AND CYCLOOLEFINES IS CONVERTED TO A SUBSTANTIALLY SATURATED DEHYDROAROMATIZATION FEEDSTOCK COMPOSED PREDOMINANTLY OF C7 PARAFFINS AND CYCLOALKANES WHILE SIMULTANEOUSLY PRODUCING HIGHLY ECONOMICALLY A MIXTURE OF ALKYL PHENOLS BY USING UP TO OLEFINE AND CYCLOOLEFINE CONTENT FO THE USATURATED C7 HEART CUT IN AN ALKYLATION REACTION UPON PHENOLS.

United States Patent 3,639,490 HEPTYL PHENOL ALKYLATION Rene P. Brown, Birt Allison, Jr., and Paul D. Meek, Big

Spring, Tex., assignors to Cosden 0i] & Chemical Company, Big Spring, Tex.

Filed Feb. 25, 1966, Ser. No. 529,979 Int. Cl. C07c 39/06 US. Cl. 260624 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to alkylation of phenol with a C- olefinic stream; to the removal of-C olefines from a catalytic gasoline stream by alkylation of phenol therewith; and to a mixture of heptyl phenols formed by phenol alkylation with a C olefine-containing stream obtained from catalytic gasoline. Removal of C olefines from said stream further produces a material suitable for subsequent processing for the recovery of aromatics.

The C C hydrocarbon mixture, predominantly 0;, comprising catalytic gasoline, is a wide ranging mixture of hydrocarbon types comprising substantially large quantities of olefines, paraflins and naphthenes with very minor quantities of aromatics, cycloolefines and di-olefines. Such feedstream must be hydrogenated before converting the naphthenes by dehydrogenation to aromatics, in which the most valuable product is toluene, but a large heterogeneous mixture of hydrocarbon types is simul taneously formed, many hydrocarbon components of which have little economic value, and with little or no decomposition of naphthenes. The unreacted material contains about 40 to 50% naphthenes, largely toluene precursors, and about 8 to 9% native toluene. The low recycle olefine content of this unreacted portion may be easily removed by hydrogenation or it can be diluted to useable levels -by simple admixing with other feedstocks of low olefine content.

According to the present invention a full boiling C C catalytic gasoline stream comprising 40 to 60% olefines, and preferably a C heart out thereof, is mixed with a phenol and the mixed stream contacted with an alkylation catalyst to convert the olefins in high yield to alkyl phenols, the alkyls of which are largely a mixture corresponding to the olefinic components originally contained in the catalytic gasoline stream, whereby to produce a valuable mixed alkyl phenol product and a relatively saturated feedstream for further formation of aromatics. While the reacted hydrocarbon stream still may contain some olefines, usually about these may be easily ice reduced by hydrogenation or bleeding prior to aromatizing.

The alkyl phenols formed herein are a mixture largely of branched chain alkyls and therein are improved in the typical use of these mixed iso-alkyl phenols as antioxidant. Thus, a valuable commercially-improved alkyl phenol product is produced while simultaneously improving the feedstream for processing to an aromatic product, by removing most of the olefinic components thereof, thus producing a better toluene-yielding feedstock for ultimate aromatization.

The phenolic reagent may be ordinary phenol or cresols produced synthetically or naturally available by distillation or extraction from commercial oils such as tar acids derived from coal tar distillate or natural petroleum phenolic extract. Thus, the phenols added for alkylation by the C olefines hereof may be natural phenol, cresols, xylenols, guaiacols, cumenols or even synthetic higher phenols such as hydroquinone, catechol or the like.

In a typical gasoline feedstream, the C7 fraction characteristics may be as shown in the following table:

1 Probably 0.5.

A C -rich olefine heart out comprising 10 to 14% of an original catalytic feedstock may be selected in a narrow boiling range of about to 215 F., and the compositions thereof may be, typically, about 50 to 52% olefines including 0.5 to 1.5% diolefines and 6 to 9% cycloolefines and the balance, saturated hydrocarbon, comprising about 15% paraffins, about 24% naphthenes and the balance, about 4%, aromatics. The C heart cut separated from the catalytic gasoline as fourteen cuts is analyzed as follows TABLE 2.HYDRO GENATED GAS CHROMATOGRAPH ANALYSIS [Weight percent] Cut Cut Out 0111; Cut Out Cut Cut Out Component (after hydrogenation) 2 4 6 7 8 10 12 13 14 Composite n-Butane 0.10 0.01 Isopnntm'm 0.29 0. 17 0. 10 0. 08 0. 08 0. 04 0. 06 0. 08 0. 11 0. 01 n-Pentane 0. 13 0.09 0. 06 0. 04 0. 03 0. 02 0. 02 0. 0. 08 0. Cyglopantane 0. 03 0. 03 0. 01 0. 01 0. 01 0. 01 0.01 0. 02 2. 8 dimethylbenzena. 2. 29 1. 63 0. 77 0. 57 0. 41 0. 24 0. 14 0. 14 0. 14 0. 83 2 methyl pentaneun- 2. 52 1. 63 0. 78 0. 59 0. 42 0. 26 0. 18 0. 22 0. 26 1. 05 3 methyl pentafle--- 6. 32 3. 78 1. 76 1. 70 1. 00 0. 46 0. 34 0. 32 0. 35 2. 00 n-Hexane 4. 12 2. 75 1. 28 0. 98 0. 73 0. 34 0. 27 0. 26 0. 29 1. 37 Methyl oyclopentane.-- 59 12. 07 6. 10 5. 02 3. 91 1. 76 1. 13 1. 01 0. 90 6. 50 3, 3 dimethyl pentane 0. 63 0. 72 0.42 0. 44 0. 34 0. 19 0. 13 0. 10 0.05 0. 48 Cyolnhoxm'm 11. 35 9.06 4. 86 4. 03 2. 94 1. 54 0. 95 0. 78 0.65 6. 5S 2, 2 dimethyl pentane-. 0.60 0.27 0. 33 0. 26 0. 14 0. 08 0. 04 0.04 0. 66 2, 2, 3 trimethyl pentane 33 0. 19 0. 20 0. 03 0. 0. 15 2, 4 dimethyl pentane- 3. 09 2. 44 1. 85 0.47 0. 39 2. 58 2, 3 dimethyl pentane 11.21 11. 65 10. 28 2 methyl hexane 22. 50 34. 21 33. 88 8. 07 16. 75 15. 65 1, 1idianiiethyilhoylelo-elntanef 0. 90 0. 90 0. 61 0. 53 0. 45 0. 12 0. 10 0. 39 1, e s ime y eye open ane 3 methymexane 15. 77 21. 3 32. 70 34. 79 32. 35 35. 46 32. 59 27. 69 29. 54 1, trans 3 dimethyl eyelopentane 2. 27 3. 66 6. 86 7. 48 6. 16 5. 24 4. 48 5. 59 1, trans 2 dimethyl cyclopentane 2. 94 2. 65 4. 07 4. 42 9. 55 5. 53 5. 14 4. 12 3 ethylpentane 0. 67 0.64 1.14 1. 26 2. 05 3, 29 3. 04 2. 28 n-Hgphann 0. 32 0. 19 0.91 0. 95 2. 69 18. 78 18. 02 6. 18 1, ois 2 dimethyl cyclopentane 0. 14 0. 16 0.33 0.42 0. 77 5. 29 6. 45 1. 63 Methyl cy 0. 04 4. 11 10. 33 1, 1, 3 trimethyl eyclopentane. 0. 26 1. 17 Ethyl eynlnpentnnn 1. 36 2. 53 0. 35 Dimethyl hexane 0. 0. 87 Benzene 1. 24 0. 17 0.04 0. 47

The description of composite hydrocarbon types is further shown as follows:

TABLE 3.A. PONA ANALYSIS An alkylation type catalyst, particularly acid clays or emperical dry acid substances as well as acid exchange resins may be used, many of which are commercially available, of which such commercially available types as Dow 50 W-X8 cation exchange resin, Am'berlyst 15 cation exchange resin, Super Filtrol Clay, and

'Filtrol Grade 24 Clay have been successfully used in the present alkylation. Other known useful alkylation catalysts such as sulfuric or phosphoric acids and Friedel-Crafts catalysts such as aluminum chloride or boron trifluoride may be used.

The resin exchange catalyst is activated by washing with concentrated sulfuric acid and then washed with methyl alcohol and dried under vacuum. The clay catalyst is then packed into a column and the stream is contacted therewith as set forth in the examples below.

The invention is further described in the single figure of drawings illustrating the steps of the process diagrammatically.

Catalytic gasoline enters the system through line 10 and is passed to a partial concentrating column still 12. The light .volatiles boiling below about 180 F. pass overhead through line 14, are condensed in a condenser 16 and a portion of the condensate is returned as reflux through line 18 to the top of the column, and the remainder passes out of the system through line 20. C concentrate having the composition as identified above, is withdrawn as a side stream through line 22 and passes to storage chamber 24 for use in the system or enters the alkylation system directly through line 26. A supply of phenol enters the system through line 28 to storage chamber 30 and thence through line 32.

A dry gas blanket such as nitrogen is maintained above the storage tank 30, entering through line 34 and exiting at vent 36 to maintain an inert, non-oxidizing atmosphere above the stored phenol in tank 30 at atmospheric pressure and 125 F.

The C -fraction in line 26 is preheated in an exchanger 40 to about 150 F. and a portion passed directly through lines 42 and 50 for purging the catalyst chamber 44, particularly to flush the same free of phenol for recovery thereof prior to change of a spent catalyst bed. In normal flow of the C -stream, it passes through line 45 where it meets and mixes with a feedstream of phenol from line 32, passing as an approximately equal molar-mixed stream of olefine to phenol by way of line 46, the mixture being further heated in exchanger 48 so that the reactor effiuent 52 will have a temperature of approximately 285 to 300 F. The mixture then passes downward through line 50 into the top of catalyst chamber 44 at a contact pressure of 25 to p.s.i.g. to insure smooth flow through the catalyst bed. The alkylation reaction is exothermic; therefore, the temperature of the mixture entering the catalyst chamber 44 will have a lower temperature than the reactor efliuent. The efliuent product in line 52 is passed to an intermediate point of a fractionating column 54. The unreacted feedstream comprising heptanes and some unreacted heptenes passing overhead in the column through line 56 is condensed to liquid in condenser 58. The condensate is extracted with caustic in a washing chamber 60 by a stream of extracting caustic entering through line 62 and withdrawn as a weak phenol solution in line 64. The washed spent substantially-saturated hydrocarbon stream overhead passes through line 66 to a hydrogenation chamber 68 and thence to an aromatizing unit 70 by way of line 72. The aromatized product in line 74 is then treated such as by extraction to recover the aromatics, typically toluene. The alkyl phenols remaining as bottoms of still 54 are withdrawn through line 76 and passed to a fractionating column 78 wherein the unreacted phenol is withdrawn overhead through line 80 and cooled by condenser 82 and recycled to line 32 as unreacted phenol returned to the system. A side stream of heptyl phenols are withdrawn through line 84 to storage, high boiling alkyl phenols and tars being withdrawn through a line 86.

The phenol is reacted in a premixed solution with the whole catalytic gasoline, or a C -heart cut thereof in proportion to the olefin content, in proportion ranging from about 0.5 to 2 mols of phenol per mol of olefin contained in the hydrocarbon, preferably about 0.75 to 1.4 mols of phenol per mol of hydrocarbon. There is reason to believe (US. Pat. No. 2,732,408) that small quantities of water tend to improve catalyst action when Filtrol Clay is the catalyst. Generally, the alkylation reaction will vary from 160 through 250 F., more usually between 190 F. to 240 F., and is carried usually under suflicient pressure to maintain the system liquid, at the reaction temperature. It is preferred, moreover, to flow the reaction mixture over the catalyst at a flow rate of about 0.5 to volumes of reaction mixture per volume of catalyst per hour.

The following examples illustrate the practice of this invention:

'EXAMPLE I A catalyst tower was packed with Dow 50W-X8 cation exchange resin converted to its acid form by washing with concentrated sulfuric acid and then with methyl alcohol, the catalyst being finally dried under vacuum for 10 hours. A mixture of equal parts by weight of a catalytic gasoline comprising about 51% olefins, 21% paraifins, 24% naphthenes and 4% aromatics, boiling in the range of 181.4 to 209.4 F. and having the characteristics shown in Table '3 and phenol were passed through the catalyst at a rate of about 5 volumes of liquid reaction mixture per volume of catalyst per hour at a temperature maintained between 220 and 240 F. The reactor efiluent had the following distillation characteristics:

ASTM distillation IBP 160 Percent:

This fraction contains approximately ten percent materials boiling higher than heptyl phenols. The bromine number on the phenol-free sample indicates a yield of 85% of theory (wt. percent).

EXAMPLE II Super Filtrol Grade Clay was dried for several days at 120 C. and packed into an experimental column as in Example I. A mixture of 945 grams of phenol and 1979 grams of C -fraction of catalytic gasoline was Prepared as reactor charge. The charge was pumped through the column containing 66 grams of clay at the rate of 76 cc./ hr. Reactor temperature during the run was 190 to 200 F. The reactor efiluent had the following distillation characteristics and by bromine number was estimated to comprise a yield of 83 weight percent of theoretical.

ASTM distillation EXAMPL'E III A solution of equal weights of C -fraction (49.5% olefines) from catalytic gasoline and phenol Was prepared as reactor feed for a column packed with 43.7 grams of Filtrol Grade 24 Clay which had been dried for three days at C. Reactor temperature throughout the run was maintained at 280 F. to 290 F. and the flow rate was 0.568 gram of feed per gram of catalyst per hour. 94% of the available olefins were removed as alkyl phenols as indicated by a material balance performed on data obtained from an analytical distillation of 903.8 grams of reactor efiluent. An analytical presentation of the distillation data is given in Table 1. It should be noted that there are no intermediate boiling fractions between the C -fraction and phenol, nor between phenol and the alkyl phenols.

A sample of the C -fraction distillate was caustic washed to remove residual phenol and then analyzed for hydrocarbon types. The following analyses reveal that the aromatics and aromatic formers were concentrated 186.9% by olefine removal.

C -fraction composition before alkylation, (vol. percent) 49.5 total olefines 25.0 saturated cycloparafiins 21.5 parafiins 4.0 aromatics 29% aromatics and aromatic formers C -fraction composition after alkylation, (vol. percent) 5.6 total olefines 46.7 saturated cycloparaffins 40.2 parafiins 7.5 aromatics 54.2% aromatics and aromatic formers The C -fraction may then be hydrogenated and passed through a platforming unit as described in US. Pat. No. 2,959,626, and the naphthenes dehydrogenated to aromatics.

The alkyl phenols recovered as still bottoms from the analytical distillation were subjected to an ASTM distillation with the following results:

Various modifications will occur to those skilled in the art. Other alkylation catalysts may be used in rates variable with the activity of the catalyst flow, and at various usefully modified alkylation temperatures and pressures. The unreacted hydrocarbon may be hydrogenated and may be further treated to remove other select fractions of some of the products identified above before or after aromatizing. It is accordingly intended that the drawings and specific examples given be regarded as illustrative and not limiting except as defined in the claims appended hereto.

What is claimed is:

1. The method of forming heptyl phenols and a naphtha base useful for aromatization, comprising distilling a catalytic naphtha to separate a 0; heart out boiling in the range of 180 to 215 F., comprising 40 to 60% olefines and a substantial quantity of parafiins and naphthenes, reacting a phenol with said heart cut 0; naphtha in proportion of about 0.5 to 2 moles of phenol per mole of olefine contained in the said naphtha at a temperature in the range of to 250 F. in the presence of an alkylation catalyst selected from the group consisting of acid clays.

7 acid exchange resins, concentrated sulfuric acid, concentrated phosphoric acid, aluminum chloride, and boron trifluoride, to form heptyl phenols and separating said heptyl phenols from unreacted hydrocarbon and phenol.

2. The method of claim 1 wherein the phenol is selected from the group consisting of phenol, cresols, xylenols, cumenol, guaiacol, hydroquinone and catechol.

3. The method of claim 1 wherein the phenol is com mercial phenol.

4. The method of claim 1 wherein the phenol is a cresylic tar acid fraction.

References Cited UNITED STATES PATENTS 8/ 1945 Schulze 208-308 8 Schueller et a1. 260-624 Pines et a1 260-6735 Buc 260-624 Peters 260-624 Kaplan 260-624 C Ashley. 260-6735 BERNARD HELFIN, Primary Examiner 10 W. B. LONE, Assistant Examiner US. Cl. X.R. 

